#-*- coding: utf-8 -*-
X=int(input())
if X>=30:
    print("Yes")
if X<30:
    print("No") X=int(input()) X int(input()) int input() input if X>=30:
    print("Yes") X>=30 X 30 print("Yes") print "Yes" if X<30:
    print("No") X<30 X 30 print("No") print "No" X=int(input()) int(input()) X
#-*- coding: utf-8 -*-
X=int(input())
if X>=30:
    print("Yes")
if X<30:
    print("No")